JPS62165572A - Fuel injection pump - Google Patents

Abstract

PURPOSE:To make it possible to control the supply amount of lubricating oil at a constant value, by attaching a hollow screw adapted to be connected with a lubricating oil pipe, to a wall which define the space of a cam chamber storing a cam shaft for a fuel injection pump, and by disposing, in the hollow section of the screw, a slidable member which may be moved by a longitudinally effected pressure differential. CONSTITUTION:A fuel injection pump has an engine driven cam shaft 5 stored in a cam chamber space 3 defined by a tappet slide hole 2 within a housing 1, and a tappet 7 abuts against the cam surface 6 of the cam shaft 5. In this arrangement, a hollow screw 13 is attached to a wall 11 which also defines the cam chamber space 3, and is connected with a lubricating oil introducing pipe through a nipple 14. Further, since this screw 13 is hollow, a slidable member 15 is disposed in the hollow section of the pipe 13, and a lubricating oil inlet port 22, an outlet port 23 and lubricating oil passages 24, 25 are formed around the slidable member 15. Further, this slidable member 15 may be moved axially by the pressure differential between the inlet and outlet ports 22, 23, thereby it is possible to control the amount of lubricating oil.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel injection pump, and more particularly to a device for supplying lubricating oil to the tappet and cam surfaces of a fuel injection pump that supplies fuel to an internal combustion engine.

[Conventional technology]

In order to extend the lifespan of parts such as the cam chamber of a fuel injection pump, in recent years, an engine lubrication system has been adopted in which lubricating oil is supplied from the same system as the engine, rather than an oil reservoir system only within the injection pump. By the way, if too much lubricant is supplied to the injection pump,
The amount of lubricating oil that overflows into the governor also increases, causing problems such as poor opening of the governor weight and unstable control characteristics of the fuel injection amount.On the other hand, if the amount of lubricating oil supplied is too small, the cam and tappet An appropriate amount of lubricating oil is required to prevent abnormal wear and noise on the sliding surfaces.

Conventionally, as shown in Japanese Patent Publication No. 44-8537, a lubricating oil supply hole was opened in the housing side of the tappet sliding part, and lubricating oil pumped from the engine through a pipe was fed into the lubricating oil supply hole. It was designed to be supplied to the sliding part between the housing and the tappet through the hole.

However, in the case of the above structure, there is a problem that the connection position of the pipe connecting the engine and the lubricating oil supply hole is restricted by the range of the tappet sliding part. There is no degree of freedom when changing the connection position, etc., and there is a drawback that interference with other parts located in the surrounding area is likely to occur. In addition, in the conventional case according to the above publication, the amount of lubricant supplied is determined by the clearance of the sliding part between the housing and tappet, and this clearance varies due to variations in the machining of the sliding surface of the housing and tappet, so high precision cannot be achieved. There was a problem in which supply could not be expected.

For this reason, generally, as shown in FIG. 3, an adapter 12 is attached to the wall 11 constituting the cam chamber space 3, a hollow screw 13 is connected to the adapter 12, and a nipple 14 connected to the hollow screw 13 is connected to the adapter 12. Lubricating oil artificial hole 13a formed in the hollow screw 13 through the lubricating oil passage 1
3b, it is necessary to provide a throttle 12a according to the lubricating oil pressure from the engine. However, this configuration has the disadvantage that it is easily clogged by foreign matter contained in the lubricating oil. In addition, in the conventional configuration described in Japanese Patent Publication No. 44-8537, since the lubricating oil inlet is provided on the outer periphery of the tappet, the reciprocating movement of the tappet incinerates the dust in the lubricating oil, which prevents clogging. However, on the other hand, it has the drawbacks mentioned above.

[Problem that the invention seeks to solve]

The present invention has been made based on the above circumstances, and its purpose is to provide a large degree of freedom in selecting the connection position of a pipe for introducing lubricating oil from an engine, and to maintain a constant supply amount of lubricating oil. The object of the present invention is to provide a fuel injection pump for an internal combustion engine that can control the amount of fuel and prevent clogging of the supply port.

[Means for solving problems]

In the present invention, a hollow screw having a hollow portion communicating with the cam chamber space is attached to a wall constituting the cam chamber space, and a sliding member movable by lubricating oil pressure from the engine is housed in the hollow portion. A lubricating oil passage is formed by this sliding member and the hollow portion of the hollow screw, and lubricating oil is supplied to the cam chamber space.

[Effect]

According to the above configuration, the connection position of the pipe for introducing lubricating oil from the engine may be anywhere on the wall constituting the cam chamber space, so the degree of freedom in selecting the connection position of the pipe is increased. Moreover, by moving the sliding member housed in the hollow part of the hollow screw by the lubricating oil pressure from the engine, lubricating oil can be supplied from the lubricating oil passage formed by the sliding member and the hollow part of the hollow screw. Therefore, the dust in the lubricating oil is incinerated in the lubricating oil passage, and the amount of lubricating oil supplied can be controlled to be constant without clogging the supply port.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described. 1st
The figure is a longitudinal cross-sectional view showing the configuration of an embodiment of the fuel injection pump according to the present invention. 1 is a housing, and this housing 1 is divided into a cam chamber space 3 and a spring housing space 4 by a tappet sliding hole 2. has been done. A cam shaft 5 rotated by an engine via a governor (not shown) is housed in the cam chamber space 3, and a cam surface 6 is formed on the cam shaft 5. A tappet 7 is slidably inserted into the tappet sliding hole 2, and this tappet 7 is inserted into the spring accommodation chamber space 4.
The cam surface 6 of the camshaft 5 is
is being pushed towards.

A cam roller 9 is rotatably attached to the tappet 7 and rotates in contact with the cam surface 6. A lower end of a pump plunger 10 is connected to the tappet 7, and an upper end of the pump plunger 10 is fitted into a pump chamber (not shown). A hollow screw (holding body) 13 is attached to a wall 11 constituting the cam chamber space 3. A nipple 14 is connected to the hollow screw 13, and a lubricating oil introducing pipe (not shown) is connected to the nipple 14.

The lubricating oil sent out from the engine is sent from the lubricating oil introduction pipe to the lubricating oil inlet hole 13a formed in the hollow screw 13 through the nipple 14.

Further, the hollow screw 13 is hollow, and a sliding member 15 is housed in this hollow portion.A lubricating oil population chamber 22, a lubricating oil outlet chamber 23, a lubricating oil outlet chamber 23,
A lubricating oil passage 24 on the side surface of the hollow screw and a lubricating oil passage 25 on the bottom surface of the hollow screw are formed. 15a is a tapered portion of the sliding member 15. 16 is a bolt, 17.
18 is a washer.

To explain the operation of the fuel injection pump of the present invention having the above configuration, since the sliding member 15 is formed with a tapered portion 15a, the lubricating oil pressure from the engine causes the component force of the hollow screw 13 to move in the direction of the arrow in the figure. Lubricating oil inlet chamber 22
The sliding member 15 can be moved due to the pressure difference between the lubricating oil outlet chamber 23 and the lubricating oil outlet chamber 23 . When the lubricating oil pressure is low, the lubricating oil is supplied through the lubricating oil passage 24 formed by the sliding member 15 and the hollow screw 13 and having a degree of fit.

In addition, when the lubricating oil pressure is high, the sliding member 15 moves due to the above-mentioned component force and pressure difference, and the lubricating oil passage 25 comes into contact with the bottom surface. The flow is restricted under the conditions of the passage 24 rather than flowing in. In other words, this device alone controls the inflow amount without being affected by the lubricating oil supply pressure from the engine, the rotation speed, or overlap of the tappet 7, etc., which are conventional disadvantages, so the amount of inflow into the cam chamber of the injection pump, etc. A constant supply is possible. Additionally, since this device is built into a hollow screw, it can be easily installed into existing equipment.

In addition, FIG. 2 (al) is a longitudinal cross-sectional view of a main part showing the configuration of another embodiment of the lubricating oil supply device in the fuel injection pump of the present invention, and FIG. FIG. 2(C) is a sectional view similar to FIG. 2(b) showing another embodiment of the blade 15b shown in FIG. 15 is provided with a notched blade 15b,
By drilling the lubricating oil inlet hole 13a of the hollow screw 13 eccentrically, the sliding member 15 is rotated, and the clogging of the passage 24 due to dirt, etc. in the lubricating oil is incinerated by rotation. . 13b is a lubricating oil passage provided in the hollow screw 13 in the form of a V-groove at the bottom, and does not need to be a groove. Further, FIG. 4 (al is a vertical cross-sectional view of a main part showing the configuration of another embodiment of the lubricating oil supply device in the fuel injection pump of the present invention, and FIG. 4(b) is a vertical sectional view of FIG.
In the sectional view taken along the line, a spring 26 is provided at the tip of the sliding member 15 (on the cam chamber side), and when the lubricating oil pressure is high due to the movement of the sliding member 15, the lubricating oil passage area becomes narrow, and conversely, the lubricating oil pressure increases. A groove 13c is formed in the hollow screw 13 so that the lower the
This is provided.

Further, FIG. 5(a) is a longitudinal cross-sectional view of main parts showing the configuration of another embodiment of the lubricating oil supply device in the fuel injection pump of the present invention,
FIG. 5(b) is a partial sectional view for explaining the operation at the tip of the sliding member 15 in the device shown in FIG. The rubber 26a is used to obtain the same effect as the device shown in FIG. 4 (a1), and as shown in FIG. It is being narrowed down.

〔Effect of the invention〕

In the fuel injection pump according to the present invention, since the hollow screw is attached to the wall constituting the cam chamber space, the pipe for introducing lubricating oil from the engine may be connected anywhere on the wall. This has the effect of increasing the degree of freedom in selecting the connection position of the vibrator, and by moving the sliding member housed in the hollow part of the hollow screw using lubricating oil pressure from the engine, the sliding member and the hollow part of the hollow screw can be moved. Since lubricating oil is supplied from the lubricating oil passage formed by The effect of being able to control it is great.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the structure of one embodiment of the fuel injection pump according to the present invention, and FIG. FIG. 2 fc) is a sectional view taken along the line I-1 shown in FIG. 2(a), and FIG. A sectional view similar to FIG. 2(b), FIG. 3 is a longitudinal sectional view of a fuel injection pump for explaining the present invention, and FIG. 4(a) is a lubricating oil supply device in a fuel injection pump according to the present invention. A vertical cross-sectional view of main parts showing the configuration of another embodiment, FIG. 4fb) is shown in FIG.
A cross-sectional view taken along the line, FIG. It is a partial sectional view of the tip for explaining the operation at the tip of the sliding member 15 in the device. 1... Housing, 2... Tappet sliding hole, 3...
・Cam chamber space, 5... cam shaft, 6... cam surface, 7.
... Tappet, 9... Cam roller, 10... Pump plunger. DESCRIPTION OF SYMBOLS 11... Wall constituting the cam chamber space 3, 12... Adapter, 13... Hollow screw (holding body>, iaa/
...Lubricating oil hole, 14...Nipple, 15...Sliding member. 15a...Taber part, 22...Lubricating oil inlet chamber, 23
... Lubricating oil outlet chamber, 24.25... Lubricating oil passage, 1
．． 3c...Groove, 26...Spring, 13d...Groove, 2
6a...Rubber.

Claims (1)

[Claims] A hollow screw having a hollow part that communicates with the cam chamber space is attached to the wall that constitutes the cam chamber space, and a sliding member that can be moved by the pressure of lubricating oil from the engine is housed in this hollow part. and a hollow portion of the hollow screw to form a lubricating oil passage to supply lubricating oil to the cam chamber space.